Officers arrested the suspect at a property in east London and took her into custody on 15 October on suspicion of intending to supply a firearm and of perverting the course of justice.

The detention followed several arrests targeting extremists suspected of planning terror attacks.

This year's Remembrance Sunday commemoration was one of the most heavily policed public events in the years following the London terrorist bombings in 2005.

Security was increased in London and other major UK cities and the terror threat was raised to "severe", after police arrested four men aged 19 to 27 over a suspected terrorist plot to target London's Cenotaph, where the Queen laid her first wreath.